Ultimate Member - Social Login 2.5.6

* Added: Filter to modify redirect URI for enterprise Gmail accounts
* Fixed: Google OAuthentication issue
* Fixed: Uninstall process

* Important LinkedIn API breaking changes
- All developers need to migrate to Version 2.0 of our APIs and OAuth 2.0 by May 1. Read more Developer Program Updates

* In this update, the API is now using the `r_lite_profile` by default: Lite Profile Fields - LinkedIn

* If you need to use the `r_basic_profile` and `r_full_profile` access permissions, you need to extend the our Linkedin API with the following UM Social Login filters:
+ um_social_login_linked_scope( $scopes ) - adding or removing supported linkedin scope
+ um_social_login_linked_profile( $profile, $info ) - merge data from api response to match field keys in the 2nd step register process

* New: Option "Keep user signed in?" added, it allows user to stay signed in
* Tweak: Update Facebook Graph to v.3.2
* Fixed: Logout before social login